Completely agree with you. Every time I see yet another template language adding some clumsy for-each loop syntax I sigh. Just let us use a normal programming language. As an example I give you every template system ever invented. Devops tooling is full of them.
One of the interesting time-related applications I worked on was involved with medicines management. If a patient was to receive a medicine around the daylight savings change over we had to make sure it wasn't either doubled-up or missed completely.
I also worked on event planning software with plenty of timezone fun with events having a timezone, the planner a potentially different timezone and it also handled flights for speakers etc who could be coming from any number of other timezones. That was mostly straight forward with decent libraries, but it certainly taught me that you need to think in (and store) timezones and not just offsets.